/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package cn.hippo4j.rpc.coder;

import cn.hippo4j.rpc.exception.CoderException;
import io.netty.buffer.ByteBuf;
import io.netty.channel.ChannelHandlerContext;
import io.netty.handler.codec.serialization.ClassResolver;
import io.netty.handler.codec.serialization.ObjectDecoder;

/**
 * According to the decoder for java objects implemented by ObjectDecoder,
 * it is necessary to ensure that the transmitted objects can be serialized
 */
public class NettyDecoder extends ObjectDecoder {

    public NettyDecoder(ClassResolver classResolver) {
        super(classResolver);
    }

    @Override
    protected Object decode(ChannelHandlerContext ctx, ByteBuf in) {
        ByteBuf byteBuf = in.retainedDuplicate();
        try {
            Object o = super.decode(ctx, in);
            if (o == null) {
                return byteBuf;
            } else {
                return o;
            }
        } catch (Exception e) {
            throw new CoderException("The encoding is abnormal, which may be caused by the failure of the transfer object to be deserialized");
        }
    }
}
